Exhaust emissions generated by motor vehicles are well recognized and acknowledged as a significant source of airborne pollutants. In efforts to control and reduce such pollutants, programs and standards have been implemented, both on the national and local levels, requiring periodic vehicle monitoring and testing to insure that emissions of the vehicle meet appropriate guidelines.
Industry response to the requirement for testing has been along two parallel paths. Both centralized and de-centralized testing networks have been proposed and implemented. A centralized testing approach provides a minimal number of test locations. While such a system can provide a high degree of security and confidence with respect to the testing procedure, it suffers from a perceived lack of convenience for the consumer, with a limited number of test facilities generating long waiting times.
The alternative path, the decentralized network approach, while more acceptable from the consumer's point of view in that it allows a large number of test facilities to be implemented, has so far been of limited acceptance by the U.S. Environmental Protection Agency (EPA). Under EPA regulations, the degree of compliance of a region with various federal standards is rated by the issuance of "credits" which determine the level of federal funding available to a state for environmental-related projects. As a result of the conclusion by the EPA that tests performed in a decentralized or distributed testing system are subject to inaccuracy, if not fraud, the credits available to a state or region for the implementation of a distributed testing network is typically one-half those available for a centralized testing system. Because of this bias, states have been reluctant to commit to decentralized systems, preferring a centralized approach even if it results in consumer dissatisfaction.
It is thus a purpose of the present invention to provide an emissions system testing methodology and apparatus which provides for an increased level of assurance of the integrity of a vehicle testing procedure.
A further purpose of the present invention is to provide such a methodology which can be applied to a distributed or decentralized testing network approach.
Yet another purpose of the present invention is to provide a testing methodology which can be implemented in testing systems and protocols of conventional structure, without significant cost or inconvenience to either the test system operator or the consumer.